The feature doesn't work on embeds, as you can see, but if you click over to the tweet on Twitter, you'll see it in action.

In the apps, you can dock the audio card, and keep listening while you browse Twitter.

In addition to NASA, others including The White House, Kevin Smith, NPR, Planet Money, Neil deGrasse Tyson, and Pitchfork are already taking advantage of the feature. Twitter has a list of accounts here.

"We’re just beginning to test the Audio Card and plan to make it available to more partners and creators in the future so that many more musical artists and creators will be able to share exclusive, in-the-moment audio to millions of listeners on Twitter," says Twitter.

The @TwitterMusic account will provide updates on accounts using the cards as time goes on.